Interação entre herbicidas e cultivares de soja sobre o nematoide de cisto Heterodera glycines

Abstract

The soybean cyst nematode is spread in all soybean producer regions. Although methods for reducing the H. glycines population are well established, little is known about the effect of herbicides and its interaction with resistant and susceptible, or even genetically modified cultivars. With the purpose to evaluate these interactions two experiments were carried out in 2006/2007 agricultural year in two different fields naturally infested. Experiments were done in Campo Alegre de Goiás (HG Type 1,3 -- ) and Gameleira de Goiás (HG Type 0 -- ) using randomized block design with treatments arranged in a factorial scheme 4 x 4 + 1. Factor A was cultivars (BRSGO Ipameri, BRSGO Luziânia, BRSGO Jataí BRS Silvânia RR) and factor B weed control (hand weeding, chlorimuron-ethyl + lactofen, chlorimuron- ethyl and haloxyfop-methyl). The additional treatment was the combination of genetically modified cultivar BRS Silvania RR and herbicide glyphosate. The use of glyphosate on cultivar BRS Silvania did not affect H. glycines population. In Campo Alegre de Goiás clorimuron + lactofen reduced the nematode population on soybean cultivar BRSGO Silvania RR at 80 DAS and the final population on soybean cultivar BRSGO Jatai. The resistant cultivar BRSGO Ipameri did not reduce the nematode population, but increase the plant development as indicated by higher dry weight, biomass and LAI.